ATHENS, Ga. -- Failed drug tests administered last week were the reason Georgia's leading rusher, Isaiah Crowell, and two other Georgia tailbacks were suspended for Saturday's game against New Mexico State, according to two people familiar with the results.

The tests were administered last Wednesday night and the results were confirmed on Tuesday.

The people spoke to The Associated Press on Wednesday on condition of anonymity because Georgia does not release the results of the tests.

According to athletic association policy, student-athletes are suspended for 10 percent of their competitions for first-time violations of the drug tests.

Crowell, a freshman, leads Georgia with 689 yards rushing and four touchdowns. Tailbacks Ken Malcome and Carlton Thomas also were suspended on Tuesday for what was announced as violations of team policy.

Georgia Athletic Director Greg McGarity sharply denied the suggestion the suspensions were delayed until after the Bulldogs' win over Florida last week.

"We don't play games around here," McGarity told The Associated Press on Wednesday. "For someone to insinuate that we are being selective like that is absurd. We don't manipulate things. We are going to conduct our program with respect and do things the right way. For anyone to claim otherwise is irresponsible."

The suspensions were announced on Tuesday, shortly after coach Mark Richt said Richard Samuel had surgery on his left ankle and could miss the remainder of the regular season.

Samuel, a junior, had 17 carries for 58 yards and the winning fourth-quarter touchdown in No. 18 Georgia's 24-20 win over Florida last week.

Samuel injured his ankle while running 9 yards to the Florida 1 on the final play of the game.

The suspensions and Samuel's injury leave Georgia severely short-handed for at least one week.

Richt said Wednesday that sophomore Brandon Harton, a former walk-on, is the leading candidate to start against New Mexico State. Harton has 11 carries for 33 yards, all against Coastal Carolina. He was awarded a scholarship in August.

Richt said freshman walk-on tailback Kyle Karempelis also could play. Richt suggested Georgia might line up with two tight ends and no tailbacks in the game.

Crowell was a much-publicized signee from Carver High School in Columbus.

Carver coach Dell McGee said Wednesday he exchanged text messages with Crowell after the suspension was announced.

"He made a mistake. Hopefully he'll learn from it," McGee told The Associated Press. "He said it won't happen again. Only time will tell."

McGee said he did not ask Crowell why he was suspended. McGee said Crowell had no history of drug problems at Carver.

Crowell, Malcome and Thomas were assigned conditioning work during the portion of Wednesday's practice that was open to media. Each player was harnessed to weighted sleds and was pulling the sleds up and down the sideline.

"I've always felt you have to have an element of punishment, something that will sting, something that will maybe make somebody think twice about doing it or maybe other guys that are watching, but you have to educate them and then you've got to love them still," Richt said before the practice.

"They are still a part of this family. We want them to understand we're supporting them through it but if the attitude is right and they're ready to learn from it and become better for it, it can become a very positive thing. Discipline can become a very positive thing in that way and everything I've seen to this point has been pointing to that very thing. So I'm pleased with how they're handling it."

Richt said he's encouraged by the way Crowell is handling the punishment.

"I think Isaiah is going to do great," Richt said. "I really do, because I saw how he has handled this mistake to this point and I really feel confident he's going to end up being stronger for it."